Stations and Lines
BART station locations (centroid), station entrances and rail lines, in KMZ format.

Download:
https://api.bart.gov/kml/bart.kmz

District Boundaries
BART election District, Adoped by the BART Board of Directors on December 1, 2011, in KMZ format.

Download:
https://api.bart.gov/kml/DirectorDistrict.kmz

Other GIS Data
Visit BART's Open Data Portal for more GIS Data.